I use my eDGe for doing my work, reading many PDF's, annotate, making notes, visualizing new ideas,send them via mail, receive answers, search the web to complete all of this and many more things.
now how do I describe that?

My eDGe is my extended office. Where ever I go, whenever I need, whenever I want.

Benham, don't forget the eDGe comes in 2 sizes: the original (EE) with a 9.7" e-ink screen and the Pocket (PE) with a 6" (I think!) screen. Other than size, they are very similar. Some people (Borisb ) have one of each.

I have the smaller PE, which I like, but I would love to have the bigger screens for really comfortable browsing, reading, and writing!

That's the Pocket eDGe, and I imagine the e-ink screen is roughly the same size as your 505.

I do transfer books from ADE. Also from Calibre. Do you hook up your 505 to a computer with a USB cable? If so, it's pretty much the same process. There's a Sony Reader app for the Android side, but I haven't tried it and don't know whether it would allow you to easily grab all the books in your Sony Library. But ADE has a decent interface. The eDGe shows up there as a drive, just like your 505 probably does, so you can drag and drop books.